Displacement type sampler



July 14, 1953 w. J. L EAs DISPLACEMENT TYPE SAMPLER .1 Y JI.

Filed Sept. 16, 1947 u u .C R E M mllzlam Qf. locas nwrzbof Clbbor'rze Patented July Y14, 1953 `DISPLACEMENT TYPE `SAMPLER William J. Leas,lTulsa, Okla., assignor to Standard Oil Development Company, a corporation of Delaware Application September 16, 1947, Serial No.7 74,205

The present invention is concerned with an improved apparatus for securing a sample of fluid from the bottom of a well. The invention is more particularly concerned with an apparatus and method for taking a sample of a iluid having a relatively high Vapor pressure or containing a relatively large amount of a gas. In accordance With the present invention, a sampling device comprising two chambers is used. One chamber is lled with mercury, and at the point of taking the sample, the mercury passes from this chamber to another as the sample enters the chamber from which the mercury is being withdrawn.

In the production of crude oils, it is very desirable and essential that representative samples be secured from the bottom of the well. This is necessary in order` to determine the characteristics of the fluid and thus control subsequent drilling and producing operations.

Various procedures have been suggested for taking representative samples. For example, various containers having surface control valves are lowered into the region from which it is desired to secure a sample. Usually the valve is opened and the sample is allowed to enter the container which in many instances is evacuated in order to facilitate the taking of the sample. One disadvantage of this procedure is that the sample of fiuid tends to flash, particularly if the fluid has a relatively high vapor pressure or contains a substantial quantity of gaseous constituents.

I have now discovered a process and apparatus by which it is possible to secure a true sample of a highly volatile iiuid. My device comprises a displacement type sampler containing two chambers, one of which contains mercury or an equivalent heavy liquid which is immiscible and nonreactive with the fluid being sampled, and which has a greater density than that iiuid, while the other chamber is preferably evacuated. I lower my device into the well hole to the desired region `at which time a clock operated valve opens the chamber containing the mercury to the fluid to be sampled. After this valve has opened the clock operated valve separating the mercury chamber from the evacuated chamber opens and the-pressure of the fluid being sampled causes it to displace the mercury into the evacuated chamber.

iv claims. (c1. 16s-1) thedrawing, at 'the surface, chamber A of my4 displacement type sampler is filled with a heavy liquid, preferably mercury. Clock operated valves l and 2 are closed. `Chamber B is evacuated and valve 3 likewise closed. I then lower my Idisplacement type sampler into the well hole to the desired depth by means of lowering means I0 attached to cable 9. Lowering means Illmay be in the form of a basket as shownand separable at points II and l2 for removal of chambers A and B, supporting lugs I5 being provided to hold the chamber assembly in place in the basket. A port 5 in the uppermost portion of the basket IIJ provides uid access through the basket to chamber A. I adjust the time control on valves I and 2 so that I have sufficient time to lower my displacement type sampler to the desired depth be#- fore thesetime control valves operate. Clock op After the displacement type sampler hasV reached the region from which it is desired to secure this sample, time control valve l opens,`

and then -time control valve 2 opens. Electric energy for the valves is fed through conductors I1 carried by cable 9. It is not considered necessary to vshow the operating details of the solenoid valves or of the timing mechanism and electrical circuits feeding the valves since such valves and timing mechanism for opening and closing circiuts after predetermined periods of time are well known and can readily be adapted to the present invention by a skilled engineer. The fluid to be sampled passes through port 5 and enters chamber A through valve l and displaces mercury from chamber A through the orice 4 and valve 2 into chamber B. In accordance with the preferred adaptation of my invention, the rate of flow is limited by the size of the orice Il. This insures that there is no decrease in the pressure of the fluid being sampled and consequently no opportunity for vaporization of same. After a sufficient time has elapsed to enable the ilow of mercury into chamber B and to secure a full sample, time operated valves l and 2 close. The broad concept of my invention is to employ a sampling device comprising two chambers and to flow a heavy liquid, which is preferably mercury,

3 from one chamber through a restricting oriiice to the other While the sample is entering the chamber from which the mercury or heavy liquid is flowing. This prevents flashing and vaporization of the Vsample and insures thesecuring of a veryv representative sample.

The process of my invention is not to' be limited by anytheory as to mode of operation, but only in and by the following claims in which it is desired to claim all novelty insofar as the prior art permits.

.What is claimed is: Y Y Y 1. Improved process for sampling a fluid in a borehole which comprises bringing said fluid into contact with a rst chamber initially filled with a heavy liquid immiscible with said borehole fluid, flowing said heavy liquid by gravity flow from said rst chamber into a second evacuated chamber through a restrictive orifice and collecting said borehole fluid sample in said first chamber asiaresult 4of the pressure differential created by said flow of heavy liquid from said first chamber into said second chamber. Y A

. 2. Process as dened by claim l wherein said heavy liquid comprises mercury. I

3. Improved displacement type sampler for borehole fluids comprising an upper chamber lled with a liquid of greater density than the fluids to beV sampled, said chamber having an eX- terior port, a valve in said port, a lower evacuated chamber, a conduit connecting the upper and lower chambers, said conduit including a restrictive orifice, a second valve in said conduit, and means for opening and closing said valves at selected times.

4. Improvedsampler according to claim 3 in which said heavy liquid filling said upper chamber comprises mercury.

wrLLrAM J. LEAs;

,References cited in the sie of Vuns paient VvUNITED STATES PATENTS Number Name Date 688,449 Tutwiler Dec. l0, 1901 2,099,877 Westall Nov. 23, 1937 2,147,983 Lindsly Feb. 23, 1939 2,161,557 Clark June 6, 1939 2,303,727 Douglas Dec. 1, 1942 2,864,464 Moore Dec. 5, 1944 FOREIGN PATENTS Number Country Date 352,600V Y Germany 1922 OTHER REFERENCES Modern Laboratory Appliances, page 272, device 6-414p, Fisher Scientific Co. and Eimer and Amend, New York, 1942. 

